Lifting sling



FIG. 1 is a perspective view from the front of the lifting sling showing the new design thereof;

FIG. 2 is a perspective view from the back of said sling;

FIG. 3 is a plan view from above of the sling, unfolded; and,

FIG. 4 is a plan view from below the sling, unfolded. 

The ornamental design for a lifting sling, as shown and described. 